Marine control knob



FIG. 1 is an isometric view of a marine control knob in accordance with the invention;

FIG. 2 is a side view of the marine control knob;

FIG. 3 is a top view of the marine control knob; and,

FIG. 4 is a bottom view of the marine control knob. 

The ornamental design for a marine control knob, as shown and described. 